I said in the thread begun by Zane (who was looking for a rifling machine) that I would try to post some pictures of the rifling machine I recently completed. This is my first attempt at posting pictures here so please bear with me. Hope this all works!

Provided this works, I will follow up in an additional post describing the machine. Cheers!

Well, I guess I must have done something right since the pictures did come through!

This project began with the assembly of the carriage and rails that was given to me by a friend who got it as an unfinished project of a deceased neighbor. Since my friend didn't seem to have the time or energy to finish it, he gave it to me. I initally thought the rails were on the light side, but it has worked out OK. I had to finish the ball bearing pull handle, the sine bar, all of the slide fittings, the rack, the mountings and aluminum plate, the inboard indexing chuck, and the outboard rotating chuck. I have not yet tried the machine out. I am on the learning curve here and intend to start by reaming out some old barrels and then re-rifling them to a larger caliber. I have yet to tackle the technical aspects of making the reamers and reaming, and making and using the box cutters (one step at a time).

Inside the carriage, is a small 32 pitch gear about two inches in diameter. The gear is fixed to the pull rod. When the carriage is drawn back using the pull rod, the rack (the long vertical part extending below the carriage) follows the sine bar and moves upward rotating the pinion gear and thus rotating the pull rod which is in turn connected to the rifling rod and cutter. Adjusting the sine bar up or down will change the twist rate of the rifling. In the picture, the sine bar is adjusted for a 10" twist. Lowering it will increase the twist as slow as you want to go. To get a faster twist on this machine, I need to install a smaller diameter pinion gear to minimuze the height of the sine bar. I haven't done this yet but probably will to get down to 8" or 9" twist. The real Pratt & Whitney double rifling machines are huge and weigh up to 10,000 lbs. They are so big that they are very rigid and sit horiontally. I found out that positioning my machine with the sine bar and rack vertically helped a lot to minimize binding and improve the smoothness of the movement. Apparantly this is what Frederick Howe discovered back in the 1850's since his machines (at the American Precision Museum, and Springfield Armory Museum) were also positioned with the sine bar vertically. Hope you all find this interesting.

Perk,
Simply awesome! This is one of those projects that I've been keen on for a while and I would very much like to add custom barrels to my miniatures. Thanks for the photos and please do keep posting information.

Thanks for the tip on the book by Howe. I have some references on cutters, but I am looking for more. Since their appears to be interest here, I will follow up in a day or two with some additional pictures with more close detail of the features of this machine including the ball bearing pull handle, the geared carriage, and the inboard indexing chuck. I was not altogether happy with the quality of the photos in the inital post and think some additional photos would help make more sense out of the project.

For those interested, here are some additional photos showing more detail;

This photo shows the detail of the ball bearing handle on the center rod which rotates as you draw the carriage back due to the action of the rack and pinion.

This next photo shows the detail of rack and pinion inside of the carriage. The pinion gear is fixed to the center rod so as the rack moves upward (as the carriage is drawn back)it turns the rod, which is in turn threaded into the rifling rod/cutter assembly.

This photo is a close up of the inboard indexing chuck. The spindle turns inside a bronze bush pressed into the aluminum plate. On the back is a large knurled nut to clamp it into a stationary position. A pin is visible at the 9:00 position to locate the holes during indexing. Holes are drilled in this indexing plate to allow divisions of 2, 3, 4, 5, 6, 7, 8, 10, 12, 15, & 32 for a corresponding number of grooves in the barrel.

This is the outboard chuck. It is basicly the same as the inboard chuck except their is no indexing plate. This chuck is a close fit in the bush and is free turning for to allow indexing the barrel (from the other end).

This is a view of the carriage from the left side of the machine. Their is plenty of grease visible on these components to accomplish smooth movement and eliminate any binding. The two screws with locknuts are for gib adjustment on the rack.

This final picture shows some detail of the inboard end piece mount and sine bar anchor. The outboard endpiece mount is identical.

Perk the Modern Gunsmithing books 1 and 11 are available as a free download here.http://www.again.net/~steve/page7d.htm
Keep up the good work. A lot of us are interested in rifling machines.
alabamaed36046

Thanks for the tip. I also have a snipe set on ebay for the Howe books mentioned by Willbird. [img]tongue.gif[/img] A friend of mine has volunteered a shot out .32 caliber black powder barrel for inital test purposes. The plan at the moment will be to drill and ream up to .375 and cut new grooves in the thing. Bore diameter will not be that critical since you can cast balls of any size to match the finished bore. The steel should be pretty mild and it will give me some good experience with cutters. My friend also has recut several muzzeloaders himself and has some box cutters to let me look at for ideas. Ultimately the plan is to bore out and recut some highpower rifle barrels made from 4140 or stainless. Bore size here will be a lot more critical. We will see!!!! [img]smile.gif[/img]

For those interested, I am attaching photos of the rifling machines at the American Precision Museum and Springfield Armory Museum. These machines are identical, one built in 1852 and the other built in 1862. They were built in Windsor, Vermont, at the Robbins & Lawrence Armory. Both of these machines were taken out of service at the Smith & Wesson plant about 1962. How's that for a long and useful life! If you look carefully, you will see many similarities in feature between these machines and the one I built. Enjoy the pictures!

The two-volume Modern Gunsmith mentioned here is available through BiblioFind at $45.00. I've found that BiblioFind, Bookfinder, Alibris, etc, are usually the best places to find books at good prices. Also, the descriptions of condition are generally more accurate than those on eBay.

If you want to look into buying versus making bore reamers, both Pacific Tool and Guage and JGS sell them.

Nice work, I was always curious how rifling is
done, could you post a close up of the tool that
does the cutting? The closest I have got to
gunwork is looking down a barrel with an eye loupe and a light, just a curious general
machinist, always wondering how something is
made.

Can't post a close up of the cutter yet because I haven't made it! If you really want to see the cutters, check out volume 2 of the Virgil Howe book "Modern Gunsmithing". He shows several cutter designs and reamers. Earlier in this thread, another interested party posted a link to a site where you can download the entire book. You will need a high speed connection though. This will be real toolmaking which should be intersting. Fortunatly I have a toolpost grinder, a surface grinder, and a heat treat oven. I have an idea I will be using them soon, but not until I get my larger lathe tooled up for drilling barrels first.

Thank you for posting the pictures. It is beautifully simple. Does the size of the rack and pinion matter? I figure a different rack and pinion size will affect the sine-bar angle setting, but is there any other considerations for determining its size?

What fits the machinery and the limits for twist you build into it. Bigger pinions slow down twist, meaning more angle is needed on sine bar, etc. Steep angles cut way down on its efficiency in turning the pinion by pulling on the rack.

The last picture of the rifling machine is shown with the sine bar set for a 10" rate of twist. As you can see, it is fairly high. The gear in the carriage is a 32 diametral pitch, and is a 32 tooth gear. I have found that with this combination raising the sine bar much higher makes operation a little problematic. The bar gets so high and the rails being only 1/2" diameter steel that you can run into some flex on the machine that interfers with operation. Slower twists require lowering the sine bar which is a direction that makes everthing smoother easier and more positive. If I were to attempt a twist faster than 10" with this machine, I would replace the carriage pinion gear with another smaller (perhaps 20 tooth) gear and matching rack, which would result in achieving the faster twists with a lower angle on the sine bar (kind of like change gears on a lathe). As the machine stands now, it is ideal for 10" or slower twist rates. I have come to realize that for a black powder gun with the very slow twist rates, this should be a very nice arrangement. On the other hand, a 10" twist will get a lot done on highpower rifle barrels also. More to come......

Perk,
I don't post here often, but I stumbled onto this thread. I'm on a slow connection too, so I know what it is like.
I do have the 2 volumes of Howe's books, a bunch of Hoffman's and Holmes' also. (all start with H ??)
Anyway, rifling machines interest me and I am looking forward to seeing more here.
I would be willing to make a CD with these books and some more that I know have references to rifling machines and cutters if you want.
Let me know... consider it my contribution to the machine.

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